Its perfectly efficient the water temp retention is gonna handle it fine you loose more heat through evaporation and the glass for sure. The drip will be a negligible impact
i recently purchased a hass computer controlled mixing valve that has a hot/cold input with a single output at the temperature you select on the dial..(82 degrees in my case) and i am very happy with it.i was lucky enough to run across one on ebay and got it for a couple hundred bucks or less.in my case, i set the temp at 82 degrees and turn on both hot and cold full blast and water comes out at the desired temperature as fast or slow as you apply the water.i run mine for half hour a day through a carbon whole house filter directly in to the tank.in my sump theres a 2"bulkhead set at the prefered elevation for sump water level so that as the tank fills and the sump begins to fill,the water will automaticly drain into the house sewer system.(through the 2" bulkhead and backflow preventer of course)..
you are coerrect.i dont use mine as a drip system. i should not have reply'd to this thread. enough said. i use my system as a lazymans water changer and as to refill after draining.
i had my overflow plug on my sump where it connects to the sewer/drain pipe of the house and overflow the sump so i stopped using mine as a drip.
http://www.angelfish.net/DripSystemcalc.php
here is a good website to tell you how much a water change you are actually doing using a drip